KR20210070012A - Printed circuit board and mehod of manufacturing thereof - Google Patents

Abstract

According to an embodiment of the present invention, a printed circuit board comprises: a first insulating layer; a second insulating layer disposed on an upper side of the first insulating layer; a first via part disposed in the first insulating layer; and a second via part disposed in the second insulating layer. The first via part includes: a first via part disposed to pass through the first insulating layer; a (1-1)^th pad disposed on an upper surface of the first insulating layer, and connected to an upper surface of the first via part; and a (1-2)^th pad disposed on a lower surface of the first insulating layer, and connected to a lower surface of the first via part. The second via part includes: a second via part disposed to pass through the second insulating layer, and having a lower surface connected to an upper surface of the (1-1)^th pad; and a second pad disposed on an upper surface of the second insulating layer and connected to an upper surface of the second via part. The (1-1)^th pad is smaller than or equal to the width of the upper surface of the first via part. Also, the second pad is smaller than or equal to the width of the upper surface of the second via part. Accordingly, the degree of design freedom of the printed circuit board can be improved.

Description

Printed circuit board and manufacturing method thereof

The embodiment relates to a printed circuit board and a method for manufacturing the same.

As the miniaturization, weight reduction, and integration of electronic components accelerate, the line width of circuits is becoming smaller. In particular, as the design rules of semiconductor chips are integrated in the nanometer scale, the circuit line width of a package board or a printed circuit board on which a semiconductor chip is mounted is reduced to several micrometers or less.

In order to increase the degree of circuit integration of the printed circuit board, that is, in order to miniaturize the line width of the circuit, various methods have been proposed. In order to prevent loss of circuit line width in the etching step to form a pattern after copper plating, a semi-additive process (SAP) method and a modified semi-additive process (MSAP) have been proposed.

Thereafter, an Embedded Trace Substrate (hereinafter referred to as 'ETS') method in which a copper foil is buried in an insulating layer to implement a finer circuit pattern is used in the art. The ETS method is advantageous in reducing the circuit pitch because there is no circuit loss due to etching because the copper foil circuit is manufactured by embedding it in the insulating layer instead of forming it on the surface of the insulating layer.

^{Meanwhile, recent efforts are being made to develop an improved 5 th} generation (5G) communication system or a pre-5G communication system in order to meet the demand for wireless data traffic. Here, the 5G communication system uses ultra-high frequency (mmWave) bands (sub 6 gigabytes (6GHz), 28 gigabytes 28GHz, 38 gigabytes 38GHz or higher frequencies) to achieve high data rates.

And, in order to alleviate the path loss of radio waves in the ultra-high frequency band and increase the propagation distance of radio waves, in the 5G communication system, beamforming, massive MIMO, and aggregation of array antennas, etc. technologies are being developed. Considering that these frequency bands can consist of hundreds of active antennas of wavelengths, the antenna system is relatively large.

Since these antennas and AP modules are patterned or mounted on a printed circuit board, low loss of the printed circuit board is very important. This means that several substrates constituting the active antenna system, ie, an antenna substrate, an antenna feeding substrate, a transceiver substrate, and a baseband substrate, must be integrated into one compact unit.

And, the printed circuit board applied to the 5G communication system as described above is manufactured in the trend of light, thin and compact, and accordingly, the circuit pattern is gradually becoming finer.

However, the printed circuit board of the prior art has significantly reduced design freedom due to the pad connected to the via, which has a problem in that the RF performance is also reduced in the 5G NR era.

Therefore, in accordance with the 5G era, a new technology for miniaturization and thinning of semiconductor package technology is required.

In the embodiment, a printed circuit board having a new structure and a method for manufacturing the same are provided.

In addition, the embodiment provides a printed circuit board including a via part having the same width of a via and a pad directly connected to the via, and a method of manufacturing the same.

In addition, the embodiment provides a printed circuit board including a via portion having a width of a via greater than a width of a pad directly connected to the via, and a method of manufacturing the same.

In addition, the embodiment provides a printed circuit board having a structure in which a plurality of via parts directly connected to each other are aligned on one vertical line in a multilayer stack structure, and a method of manufacturing the same.

In addition, the embodiment provides a printed circuit board having a zigzag structure in which a plurality of via portions directly connected to each other are not aligned on one vertical line and are shifted in a multilayer stack structure, and a method of manufacturing the same.

The technical problems to be achieved in the proposed embodiment are not limited to the technical problems mentioned above, and other technical problems not mentioned are clear to those of ordinary skill in the art to which the proposed embodiment belongs from the description below. will be able to be understood

A printed circuit board according to an embodiment includes a first insulating layer; a second insulating layer disposed over the first insulating layer; a first via portion disposed in the first insulating layer; and a second via part disposed in the second insulating layer, wherein the first via part includes a first via part passing through the first insulating layer and disposed on an upper surface of the first insulating layer, , a 1-1 pad connected to an upper surface of the first via part, and a 1-2 th pad disposed on a lower surface of the first insulating layer and connected to a lower surface of the first via part; The second via part may include a second via part passing through the second insulating layer and having a lower surface connected to the upper surface of the 1-1 pad, and a second via part disposed on the upper surface of the second insulating layer, and the second via part a second pad connected to an upper surface of the , wherein the 1-1 pad is smaller than or equal to a width of an upper surface of the first via part, and the second pad is smaller than a width of an upper surface of the second via part less than or equal

In addition, each of the first via part and the second via part includes an upper surface having a first width and a lower surface having a second width smaller than the first width.

In addition, each of the 1-1 pad and the second pad has a third width smaller than the first width or the second width.

In addition, an upper surface of the first via part includes a first region in contact with a lower surface of the second insulating layer and a second region in contact with a lower surface of the second pad.

In addition, the upper surface of the first via part includes a third region in contact with the upper surface of the second via part.

In addition, the printed circuit board may include a third insulating layer disposed under the first insulating layer; and a third via part disposed in the third insulating layer, wherein the third via part includes a third pad disposed on a lower surface of the third insulating layer, and disposed in the third insulating layer, wherein a lower surface of the third via part is disposed in the third insulating layer. and a third via part connected to an upper surface of the third pad and having an upper surface connected to the first-second pad.

In addition, the first and second pads may have the second width or a third width smaller than the second width.

In addition, a lower surface of the first via part may have a first region in contact with an upper surface of the third insulating layer, a second region in contact with an upper surface of the third pad, and an upper surface of the third via part. and a third area.

In addition, the second insulating layer and the third insulating layer include photoimageable dielectics (PID).

In addition, the first insulating layer includes a thermosetting resin.

In addition, the center of each of the 1-1 pad, the 1-2 pad, the first via part, the second via part, the second pad, the third via part, and the third pad is one aligned on the same vertical line.

On the other hand, the manufacturing method of the printed circuit board according to the embodiment comprises the steps of preparing a first insulating layer; forming a first via hole in the first insulating layer; forming a first via portion filling the first via hole in the first insulating layer; forming a second insulating layer on the upper surface of the first insulating layer and forming a third insulating layer below the lower surface of the first insulating layer; forming a second via hole in the second insulating layer and forming a third via hole in the third insulating layer; forming a second via part filling the second via hole in the second insulating layer and forming a third via part filling the third via hole in the third insulating layer, the first via part; a first via part passing through the first insulating layer, a 1-1 pad disposed on an upper surface of the first insulating layer and connected to the upper surface of the first via part; a pad 1-2 disposed on a lower surface and connected to a lower surface of the first via part, the second via part passing through the second insulating layer, and a lower surface of the pad 1-1 a second via part connected to an upper surface, and a second pad disposed on the upper surface of the second insulating layer and connected to the upper surface of the second via part, wherein the third via part comprises: a third pad disposed on a lower surface, a third via part disposed in the third insulating layer, a lower surface connected to an upper surface of the third pad, and a third via part having an upper surface connected to the first-2 pads; The 1-1 pad may be smaller than or equal to a width of an upper surface of the first via part, the second pad may be smaller than or equal to a width of an upper surface of the second via part, and the third pad may include: 3 It is less than or equal to the width of the lower surface of the via part.

In addition, each of the first via part and the second via part includes an upper surface having a first width and a lower surface having a second width smaller than the first width, and the third via part includes: It includes an upper surface having a width and a lower surface having the first width.

In addition, each of the 1-1 pad and the second pad has the first width or a third width smaller than the second width, and the 1-2 pad has the second width or the second width. has a smaller third width.

In addition, an upper surface of the first via part has a first region in contact with a lower surface of the second insulating layer, a second region in contact with a lower surface of the second pad, and an upper surface of the second via part. and a third area.

In addition, a lower surface of the first via part may have a first region in contact with an upper surface of the third insulating layer, a second region in contact with an upper surface of the third pad, and an upper surface of the third via part. and a third area.

In addition, the second insulating layer and the third insulating layer include a photoimageable dielectics (PID), and the first insulating layer includes a thermosetting resin.

In addition, the center of each of the 1-1 pad, the 1-2 pad, the first via part, the second via part, the second pad, the third via part, and the third pad is one aligned on the same vertical line.

According to an embodiment, in a printed circuit board having a multilayer structure, each via portion interconnected includes a via part penetrating an insulating layer and a pad disposed on one surface of the via part. In this case, in the printed circuit board according to the embodiment, the width of the pad is not greater than the width of the one surface of the via part. In other words, the width of each via part included in the printed circuit board may be equal to or smaller than the width of one surface of the via part.

According to this, the printed circuit board according to the embodiment may increase the separation distance between the plurality of via portions, and thus, it is easy to implement a fine pattern of the circuit pattern, thereby increasing the circuit density.

In addition, in the embodiment, the design freedom of the printed circuit board as a whole can be improved according to the design change of the via part, and thus fine pattern implementation and board reliability can be secured.

In addition, in the embodiment, the centers of the via portions directly connected to each other in the vertical direction may be arranged to be aligned on the same vertical line, or alternatively, may be arranged in a zigzag manner to be shifted from each other. Here, the aligned or zigzag-arranged portions may be non-apartments of respective vias, and may alternatively be pads of each via, and otherwise include both non-apartments and pads of each via. Accordingly, the shape or position of the via part can be freely changed according to the design of the circuit pattern required in the printed circuit board including the via part, and thus the degree of design freedom can be improved.

1 is a view showing a printed circuit board according to a comparative example.
2 is a view showing a printed circuit board according to the first embodiment.
3 is a view comparing the separation distances between a plurality of via parts in the printed circuit boards of the comparative example and the first embodiment.
4 to 10 are views showing the manufacturing method of the printed circuit board according to the first embodiment shown in FIG. 2 in order of process.
11 is a view showing a printed circuit board according to a second embodiment.
12 is a view showing a printed circuit board according to a third embodiment.
13 is a view showing a printed circuit board according to a fourth embodiment.
14 is a view showing a printed circuit board according to a fifth embodiment.
15 is a view showing a printed circuit board according to a sixth embodiment.
16 is a view showing a printed circuit board according to a seventh embodiment.

Hereinafter, the embodiments disclosed in the present specification will be described in detail with reference to the accompanying drawings, but the same or similar components are assigned the same reference numerals regardless of reference numerals, and redundant description thereof will be omitted. The suffixes "module" and "part" for the components used in the following description are given or mixed in consideration of only the ease of writing the specification, and do not have a meaning or role distinct from each other by themselves. In addition, in describing the embodiments disclosed in the present specification, if it is determined that detailed descriptions of related known technologies may obscure the gist of the embodiments disclosed in the present specification, the detailed description thereof will be omitted. In addition, the accompanying drawings are only for easy understanding of the embodiments disclosed in the present specification, and the technical spirit disclosed herein is not limited by the accompanying drawings, and all changes included in the spirit and scope of the present invention , should be understood to include equivalents or substitutes.

Terms including an ordinal number, such as first, second, etc., may be used to describe various elements, but the elements are not limited by the terms. The above terms are used only for the purpose of distinguishing one component from another.

When a component is referred to as being “connected” or “connected” to another component, it is understood that the other component may be directly connected or connected to the other component, but other components may exist in between. it should be On the other hand, when it is said that a certain element is "directly connected" or "directly connected" to another element, it should be understood that no other element is present in the middle.

The singular expression includes the plural expression unless the context clearly dictates otherwise.

In the present application, terms such as "comprises" or "have" are intended to designate that a feature, number, step, operation, component, part, or combination thereof described in the specification exists, but one or more other features It should be understood that this does not preclude the existence or addition of numbers, steps, operations, components, parts, or combinations thereof.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 is a view showing a printed circuit board according to a comparative example. Fig. 1 (a) is a view showing a printed circuit board including a buried circuit pattern manufactured by the ETS method, and Fig. 1 (b) is a view showing a printed circuit board including a general protruding circuit pattern.

Referring to (a) of Figure 1, the printed circuit board according to the comparative example includes a circuit pattern manufactured by the ETS method.

Specifically, the printed circuit board manufactured by the ETS method includes an insulating layer 11 , a circuit pattern 12 , and a via portion 16 . At this time, although it is illustrated that the circuit pattern 12 is disposed only under the insulating layer 11 in the drawing, the circuit pattern is substantially additionally disposed on the upper surface of the insulating layer 11 having a protruding structure.

The circuit pattern 12 is embedded in the insulating layer 11 .

Preferably, the circuit pattern 12 is buried in the lower region of the insulating layer 11 . Accordingly, the lower surface of the circuit pattern 12 is disposed on the same plane as the lower surface of the insulating layer 11 .

An upper circuit pattern (not shown) is additionally disposed on the upper surface of the insulating layer 11 , wherein the upper circuit pattern has a structure protruding above the upper surface of the insulating layer 11 .

A via portion 16 is disposed in the insulating layer 11 .

At this time, the via part 15 is disposed in the insulating layer 11 , the via part 15 passing through the insulating layer 11 , and a first pad ( ) buried in the lower region of the insulating layer 11 . 13) and a second pad 14 disposed on the upper surface of the insulating layer 11 .

In this case, the first pad 14 has a first width w1, and the second pad 15 has a second width w2. The first width w1 may be the same as the second width w2 , but differently than the second width w2 .

In addition, the lower surface of the via part 15 is in contact with the upper surface of the first pad 13 and has a third width w3 . In addition, the upper surface of the via part 15 is in contact with the lower surface of the second pad 14 and has a fourth width w4 . In this case, the third width w3 is smaller than the fourth width w4 , and accordingly, the via part 15 has a shape in which the width gradually decreases from the upper part to the lower part.

Meanwhile, the third width w3 of the lower surface of the via part 15 is smaller than the first width w1 of the first pad 13 . In addition, the fourth width w4 of the upper surface of the via part 15 is smaller than the second width w2 of the second pad 14 . That is, the first pad 13 and the second pad 14 have a structure extending in the horizontal direction respectively above and below the via part 15 .

Meanwhile, in recent years, circuit patterns have been gradually refined. And, in the case of a fine circuit pattern having a width/interval of 15 μm/15 μm or less, the outermost layer must be implemented by the ETS method. That is, in the case of a micro circuit pattern in which the circuit pattern of the outermost layer has a width of 15 μm and each circuit pattern must be disposed 15 μm or less apart, the circuit pattern must be formed by the ETS method to form a stable micro circuit pattern. is possible to form

However, in the printed circuit board in the comparative example as described above, the first width w1 of the first pad 13 is greater than the third width w3 of the lower surface of the via part 15 , and the via part 15 ), the second width w2 of the second pad 14 is greater than the fourth width w4 of the upper surface. Accordingly, the separation distance between the neighboring via portions is reduced. In other words, in the printed circuit board in the comparative example, the separation distance w5 between the adjacent first pads 13 may be reduced.

In other words, in the printed circuit board in the comparative example, the spacing between the first pads 13 is smaller than the spacing between the lower regions of the adjacent via parts.

Referring to FIG. 1B , a printed circuit board according to a comparative example includes a circuit pattern having a protruding structure.

Specifically, the printed circuit board includes an insulating layer 21 , a circuit pattern 22 , and a via portion 26 . At this time, although the circuit pattern 22 is illustrated as being disposed only under the insulating layer 21 in the drawing, the circuit pattern is substantially additionally disposed on the upper surface of the insulating layer 21 having a protruding structure.

The circuit pattern 22 has a structure protruding under the lower surface of the insulating layer 21 . Accordingly, the upper surface of the circuit pattern 22 is disposed on the same plane as the lower surface of the insulating layer 21 .

A via portion 26 is disposed in the insulating layer 21 .

In this case, the via part 26 is disposed in the insulating layer 21 , the via part 25 passing through the insulating layer 21 , and a first pad protruding under the lower surface of the insulating layer 21 . 23) and a second pad 24 disposed on the upper surface of the insulating layer 21 .

In this case, the first pad 24 has a first width w1', and the second pad 25 has a second width w2'. The first width w1 ′ may be the same as the second width w2 ′, but differently than the second width w2 ′.

Also, the lower surface of the via part 25 contacts the upper surface of the first pad 23 and has a third width w3 ′. In addition, the upper surface of the via part 25 is in contact with the lower surface of the second pad 24 and has a fourth width w4 ′. In this case, the third width w3' is smaller than the fourth width w4', and accordingly, the via part 25 has a shape in which the width gradually decreases from the upper part to the lower part.

Meanwhile, the third width w3 ′ of the lower surface of the via part 25 is smaller than the first width w1 ′ of the first pad 23 . In addition, a fourth width w4 ′ of the top surface of the via part 25 is smaller than a second width w2 ′ of the second pad 24 . That is, the first pad 23 and the second pad 24 have a structure extending in the horizontal direction respectively above and below the via part 25 .

In this case, in the printed circuit board in the comparative example as described above, the first width w1' of the first pad 23 is greater than the third width w3' of the lower surface of the via part 25, and the via part The second width w2' of the second pad 24 is greater than the fourth width w4' of the upper surface of (25). Accordingly, the separation distance between the neighboring via portions is reduced. In other words, in the printed circuit board in the comparative example, the separation distance w5 ′ between the adjacent first pads 23 may be reduced.

In addition, as 5G technology develops in recent years, interest in printed circuit boards that can reflect this is increasing. At this time, in order to apply the 5G technology, the printed circuit board must have a high multi-layer structure, and the circuit pattern must be refined accordingly. However, in the comparative example, although it is possible to form a fine pattern due to the structure of the via part as described above, there is a problem in that the circuit density in the space between the via parts is lowered.

FIG. 2 is a view showing a printed circuit board according to the first embodiment, and FIG. 3 is a view comparing the separation distances between a plurality of via parts in the printed circuit boards of the comparative example and the first embodiment.

2 and 3 , the printed circuit board 100 includes an insulating layer 110 , via portions 120 , 130 , 140 , 150 , 160 , and a circuit pattern 135 .

The printed circuit board 100 represents the electrical wiring connecting the circuit parts based on the circuit design as a wiring diagram, and the electrical conductor can be reproduced on the insulator. In addition, the printed circuit board 100 may mount electrical components and form wiring for connecting them in a circuit, and may mechanically fix components other than the electrical connection function of the components.

The insulating layer 110 may have a plurality of stacked structures. Preferably, the insulating layer 110 includes a first insulating layer 111 , a second insulating layer 112 , a third insulating layer 113 , a fourth insulating layer 114 , and a fifth insulating layer 115 . can do.

The first insulating layer 111 may be a central insulating layer located at the center of the insulating layers 110 having a plurality of stacked structures. The first insulating layer 111 may be a core insulating layer. However, this is only an embodiment, and the printed circuit board 100 may be a coreless substrate, and thus the first insulating layer 111 may be a general insulating layer.

The first insulating layer 111 may be rigid or flexible. For example, the first insulating layer 111 may include glass or plastic. In detail, the first insulating layer 111 may include chemically strengthened/semi-tempered glass such as soda lime glass or aluminosilicate glass, polyimide (PI), or polyethylene terephthalate. , PET), propylene glycol (PPG), reinforced or soft plastic such as polycarbonate (PC), or may include sapphire.

In addition, the first insulating layer 111 may include an optical isotropic film. For example, the first insulating layer 111 may include cyclic olefin copolymer (COC), cyclic olefin polymer (COP), optical isotropic polycarbonate (PC), or optical isotropic polymethyl methacrylate (PMMA). can

Also, the first insulating layer 111 may be bent while having a partially curved surface. That is, the first insulating layer 111 may be bent while partially having a flat surface and partially having a curved surface. In detail, the end of the first insulating layer 111 may be curved while having a curved surface, or may have a surface including a random curvature and may be curved or bent.

In addition, the first insulating layer 111 may be a flexible substrate having a flexible characteristic. Also, the first insulating layer 111 may be a curved or bent substrate. In this case, the first insulating layer 111 may represent the electrical wiring connecting the circuit components based on the circuit design as a wiring diagram, and the electrical conductor may be reproduced on the insulating material. In addition, the first insulating layer 111 may form wiring for mounting electrical components and connecting them in a circuit, and may mechanically fix components other than the electrical connection function of the components.

The second insulating layer 112 may be disposed on the upper surface of the first insulating layer 111 .

The third insulating layer 113 may be disposed under the lower surface of the first insulating layer 111 .

The fourth insulating layer 114 may be disposed on the upper surface of the second insulating layer 112 .

The fifth insulating layer 115 may be disposed under the lower surface of the third insulating layer 113 .

The second insulating layer 112 , the third insulating layer 113 , the fourth insulating layer 114 , and the fifth insulating layer 115 may include a photocurable resin or a photosensitive resin. That is, the second insulating layer 112 , the third insulating layer 113 , and the fourth insulating layer may be formed of a PID (photoimageable dielectics) material.

To this end, the second insulating layer 112 , the third insulating layer 113 , the fourth insulating layer 114 , and the fifth insulating layer 115 are formed of an epoxy resin, a photoinitiator, a silicon-based filler, and a curing agent. and the like. For example, the second insulating layer 112 , the third insulating layer 113 , the fourth insulating layer 114 , and the fifth insulating layer 115 include a photocurable resin film laminated or a photocurable resin paste or liquid. It may be formed by coating. At this time, in one example, the photocurable resin material is photocurable polyhydroxystyrene (PHS), photocurable polybenzoxazole (PBO), photocurable polyimide (PI), photocurable benzocyclobutene (BCB), photocurable It may include any one or more selected from chemical conversion polysiloxane, photocurable epoxy, and novolac resin.

In the embodiment, the second insulating layer 112, the third insulating layer 113, the fourth insulating layer 114, and the fifth insulating layer 115 are formed of a photocurable resin, so that exposure and development are used. A small size of the circuit to be cleaned pattern and the fine via portion may be formed.

Meanwhile, circuit patterns (not shown) are formed on the surfaces of the first insulating layer 111 , the second insulating layer 112 , the third insulating layer 113 , the fourth insulating layer 114 , and the fifth insulating layer 115 . This can be placed In this case, reference numerals are given only to the circuit pattern 135 disposed on the upper surface of the second insulating layer 112 in the drawing.

The circuit pattern has a structure buried in each of the first insulating layer 111 , the second insulating layer 112 , the third insulating layer 113 , the fourth insulating layer 114 , and the fifth insulating layer 115 . It can be manufactured by ETS (Embedded Trace Substrate) method. However, the embodiment is not limited thereto, and the additive process, the subtractive process, which is a typical manufacturing process of a printed circuit board, so that the circuit pattern has a structure protruding above the surface of each insulating layer Process), Modified Semi Additive Process (MSAP), and Semi Additive Process (SAP) methods, and a detailed description thereof will be omitted here.

The circuit pattern is a wiring that transmits an electrical signal, and may be formed of a metal material having high electrical conductivity. To this end, the circuit pattern 120 includes at least one selected from gold (Au), silver (Ag), platinum (Pt), titanium (Ti), tin (Sn), copper (Cu), and zinc (Zn). It may be formed of a metallic material. In addition, the circuit pattern is formed of at least one metal material selected from gold (Au), silver (Ag), platinum (Pt), titanium (Ti), tin (Sn), copper (Cu), and zinc (Zn) having excellent bonding strength. It may be formed of a paste or solder paste containing Preferably, the circuit pattern may be formed of copper (Cu), which has high electrical conductivity and is relatively inexpensive.

Meanwhile, a via portion may be disposed in each insulating layer.

The first via part 120 is disposed in the first insulating layer 111 . The first via part 120 includes a first via part 121 that penetrates through the first insulating layer 111 , and is disposed on the upper and lower surfaces of the first insulating layer 111 , respectively, and includes the first via part 121 . It includes first pads 122 and 123 connected to the via part 121 .

The first via part 121 may be formed by filling the first via hole VH1 penetrating the first insulating layer 111 with a conductive material.

The first via hole VH1 may be formed by any one of mechanical, laser, and chemical processing methods. When the first via hole VH1 is formed by machining, methods such as milling, drilling, and routing may be used, and when formed by laser processing, UV or CO _{A two-} laser method may be used, and in the case of being formed by chemical processing, the first insulating layer 111 may be opened using chemicals including aminosilane, ketones, and the like.

On the other hand, the processing by the laser is a cutting method in which a part of the material is melted and evaporated by concentrating optical energy on the surface to take a desired shape, and complex formation by a computer program can be easily processed, and in other methods, cutting Even difficult composite materials can be machined.

In addition, the processing by the laser can have a cutting diameter of at least 0.005mm, and has a wide advantage in a range of possible thicknesses.

As the laser processing drill, it is preferable to use a YAG (Yttrium Aluminum Garnet) laser, a CO ₂ laser, or an ultraviolet (UV) laser. The YAG laser is a laser that can process both the copper foil layer and the insulating layer, and the CO ₂ laser is a laser that can process only the insulating layer.

When the first via hole VH1 is formed, the inside of the through hole is filled with a conductive material to form the first via part 121 . The metal material forming the first via part 121 may be any one material selected from copper (Cu), silver (Ag), tin (Sn), gold (Au), nickel (Ni), and palladium (Pd). The conductive material may be filled using any one or a combination of electroless plating, electrolytic plating, screen printing, sputtering, evaporation, inkjetting and dispensing. can

At this time, the first via holes VH1 formed in the first insulating layer 111 in the embodiment are via holes VH2, VH3, VH4, and VH4 formed in the other insulating layers 112, 113, 114, 115. VH5) can be formed in a different way. That is, the remaining insulating layers 112 , 113 , 114 , and 115 excluding the first insulating layer 111 are formed of a photosensitive material, and thus, through processes such as exposure and development, the via holes VH2, VH3, VH4, VH5) may be formed. On the other hand, the first insulating layer 111 may be formed of a material different from that of the second to fifth insulating layers 112 , 113 , 114 , and 115 . The second to fifth via holes VH2 , VH3 , VH4 , and VH5 may be formed by any one processing method among mechanical, laser, and chemical processing, which is different from the second to fifth via holes VH2 , VH3 , VH4 , and VH5 . However, the embodiment is not limited thereto, and the first via hole VH1 may also be formed in the same manner as the second to fifth via holes VH2 , VH3 , VH4 , and VH5 .

First pads 122 and 123 may be disposed on the upper and lower surfaces of the first insulating layer 111 .

Preferably, the first-first pad 122 connected to the upper surface of the first via part 121 may be disposed on the upper surface of the first insulating layer 111 . The first-first pad 122 may be one of a plurality of circuit patterns disposed on the upper surface of the first insulating layer 111 .

Also, a 1-2 th pad 123 connected to a lower surface of the first via part 121 may be disposed on a lower surface of the first insulating layer 111 . The 1-2 first pad 123 may be one of a plurality of circuit patterns disposed on the lower surface of the first insulating layer 111 .

The width of the upper surface and the lower surface of the first via part 121 may be different from each other. Preferably, a top surface of the first via part 121 may have a first width W1 . In addition, a lower surface of the first via part 121 may have a second width W2 smaller than the first width W1 . That is, the first via part 121 may have a cylindrical shape in which the width gradually decreases from the upper surface to the lower surface. Accordingly, the first width W1 and the second width W2 may mean a diameter of an upper surface and a diameter of a lower surface of the first via part 121 , respectively.

The first-first pad 122 may be a capture pad of the first via part 120 . The width of the upper surface and the lower surface of the first-first pad 122 may be the same. Preferably, the first-first pad 122 may have a first width W1 corresponding to a top surface of the first via part 121 .

The first-second pad 123 may be a land pad of the first via part 120 . The width of the upper surface and the lower surface of the first-second pad 123 may be the same. Preferably, the 1-2 first pad 123 may have a first width W1 corresponding to the top surface of the first via part 121 .

That is, the first-first pad 122 and the first-second pad 123 may have a first width W1 corresponding to the top surface of the first via part 121 .

As described above, in the embodiment, the width of the first-first pad 122 is the same as the width of the upper surface of the first via part 121 . Accordingly, in the embodiment, the separation distance W3 between the plurality of first via portions 120 disposed in the first insulating layer 111 may be increased compared to the comparative example illustrated in FIG. 1 . That is, in the embodiment, the separation distance between the top surfaces of the plurality of first via parts and the separation distance between the plurality of first-first pads may be the same. Accordingly, in the embodiment, the separation distance between the plurality of first via portions may be increased, thereby improving other circuit density and design freedom.

Meanwhile, a second via portion 130 is disposed in the second insulating layer 112 . The second via part 130 includes a second via part 131 that passes through the second insulating layer 112 and a second via part 131 that is disposed on the upper surface of the second insulating layer 112 and is disposed on the second via part ( A second pad 132 connected to the upper surface of the 131 may be included.

In this case, the lower surface of the second via part 131 may be disposed in direct contact with the upper surface of the first-first pad 122 of the first via part 120 .

The upper and lower surfaces of the second via part 131 may have different widths. Preferably, an upper surface of the second via part 131 may have a first width W1 , and a lower surface of the second via part 131 may have a second width W2 smaller than the first width W1 . ) can have

The second pad 132 disposed on the upper surface of the second via part 131 may have a first width W1 corresponding to the upper surface of the second via part 131 . A lower surface of the second pad 132 may directly contact an upper surface of the second via part 131 . Specifically, the lower surface of the second pad 132 may contact only the upper surface of the second via part 131 while not in contact with the upper surface of the second insulating layer 112 .

At this time, in the comparative example, the insulating layer 11 was formed of a thermosetting resin. Accordingly, a via hole for forming the via part may be formed by a laser process. In this case, as in the embodiment, when the width of the first-first pad 122 is the same as the width of the upper surface of the first via part 121 , the second via hole ( Even if the formation position of VH2 is slightly shifted, the second via hole VH2 may penetrate up to the lower first insulating layer 111 , and thus a defect may occur. That is, in the comparative example, the 1-1 pad served as a stopper for performing the laser process, and thus there was a limit in reducing the width of the 1-1 pad.

On the other hand, the second insulating layer 112 in the embodiment is formed of a photocurable resin as described above. Accordingly, the second via hole VH2 for forming the second via part 131 in the embodiment is formed through exposure and development processes, and thus is correlated with the width of the first-first pad 1122 . A via hole can be formed only in a desired insulating layer without the need. Accordingly, in the embodiment, the width of the first-first pad 122 may be reduced as described above, and thus the separation distance between the plurality of first via portions 120 may be increased.

Meanwhile, a third via portion 140 is disposed in the third insulating layer 113 . The third via part 140 includes a third via part 141 disposed through the third insulating layer 113 and a third via part 141 disposed on a lower surface of the third insulating layer 113 . A third pad 142 connected to the lower surface of the 141 may be included.

In this case, the upper surface of the third via part 141 may be disposed in direct contact with the lower surface of the first second pad 123 of the first via part 120 .

The upper and lower surfaces of the third via part 141 may have different widths. Preferably, an upper surface of the third via part 141 may have a second width W2 , and a lower surface of the third via part 141 may have a first width W1 greater than the second width W2 . ) can have

The third pad 142 disposed on the lower surface of the third via part 141 may have a first width W1 corresponding to the lower surface of the third via part 141 . An upper surface of the third pad 142 may directly contact a lower surface of the third via part 141 . Specifically, the upper surface of the third pad 142 may contact only the lower surface of the third via part 141 while not in contact with the lower surface of the third insulating layer 113 .

Meanwhile, a fourth via part 150 is disposed in the fourth insulating layer 114 . The fourth via part 150 includes a fourth via part 151 that passes through the fourth insulating layer 114 , and a fourth via part 151 that is disposed on the upper surface of the fourth insulating layer 114 . A fourth pad 152 connected to the upper surface of the 151 may be included.

In this case, the lower surface of the fourth via part 151 may be disposed in direct contact with the upper surface of the second pad 132 of the second via part 130 .

The upper and lower surfaces of the fourth via part 151 may have different widths. Preferably, an upper surface of the fourth via part 151 may have a first width W1 , and a lower surface of the fourth via part 151 may have a second width W2 smaller than the first width W1 . ) can have

The fourth pad 152 disposed on the upper surface of the fourth via part 151 may have a first width W1 corresponding to the upper surface of the fourth via part 151 . A lower surface of the fourth pad 152 may directly contact an upper surface of the fourth via part 151 . Specifically, the lower surface of the fourth pad 152 may contact only the upper surface of the fourth via part 151 while not in contact with the upper surface of the fourth insulating layer 114 .

In addition, similarly to the second via part 130 , a fourth via hole constituting the fourth via part 151 is irrespective of the width of the second pad 132 of the second via part 130 . VH4) may be stably formed, and accordingly, the width of the second pad 132 may be the same as that of the upper surface of the second via part 131 .

Meanwhile, a fifth via portion 160 is disposed in the fifth insulating layer 115 . The fifth via part 160 includes a fifth via part 161 that passes through the fifth insulating layer 115 , and a fifth via part 161 that is disposed on a lower surface of the fifth insulating layer 115 . A fifth pad 162 connected to the lower surface of the 161 may be included.

In this case, the upper surface of the fifth via part 161 may be disposed in direct contact with the lower surface of the third pad 142 of the third via part 140 .

The upper and lower surfaces of the fifth via part 161 may have different widths. Preferably, an upper surface of the fifth via part 161 may have a second width W2 , and a lower surface of the fifth via part 161 may have a first width W1 greater than the second width W2 . ) can have

The fifth pad 162 disposed on the lower surface of the fifth via part 161 may have a first width W1 corresponding to the lower surface of the fifth via part 161 . An upper surface of the fifth pad 162 may directly contact a lower surface of the fifth via part 161 . Specifically, the upper surface of the fifth pad 162 may contact only the lower surface of the fifth via part 161 while not in contact with the lower surface of the fifth insulating layer 115 .

Also, like the second via part 130 or the fourth via part 150 , the fifth via part 161 is irrespective of the width of the third pad 142 of the third via part 140 . It is possible to stably form the fifth via hole VH5 constituting the . Accordingly, the width of the third pad 142 may be the same as that of the lower surface of the third via part 141 .

Meanwhile, in the first embodiment, the first to fifth via portions 120 , 130 , 140 , 150 , and 160 may be arranged on the same vertical line CL.

Preferably, the centers of the first via part 121 and the first pads 122 and 123 constituting the first via part 120 may be aligned on one vertical line CL.

In addition, each center of the second via part 131 and the second pad 132 constituting the second via part 130 is the first via part 121 constituting the first via part 120 . And it may be aligned with the center of the first pads 122 and 123 on one vertical line CL.

In addition, the centers of the third via part 141 and the third pad 142 constituting the third via part 140 are respectively the first via part 121 , the first pads 122 and 123 , and the second via part 121 . Each center of the second via part 131 and the second pad 132 may be aligned on one vertical line CL.

In addition, the center of each of the fourth via part 151 and the fourth pad 152 constituting the fourth via part 150 is the first via part 121 , the first pads 122 and 123 , and the The center of each of the second via part 131 , the second pad 132 , the third via part 141 , and the third pad 142 may be aligned on one vertical line CL.

In addition, the center of each of the fifth via part 161 and the fifth pad 162 constituting the fifth via part 150 is the first via part 121 , the first pads 122 and 123 , and the One center of each of the second via parts 131 , the second pad 132 , the third via part 141 , the third pad 142 , the fourth via part 151 and the fourth pad 152 is formed. It may be aligned on the vertical line CL.

According to an embodiment, in a printed circuit board having a multilayer structure, each via portion interconnected includes a via part penetrating an insulating layer and a pad disposed on one surface of the via part. In this case, in the printed circuit board according to the embodiment, the width of the pad is not greater than the width of the one surface of the via part. In other words, the width of each via part included in the printed circuit board may be equal to or smaller than the width of one surface of the via part.

According to this, the printed circuit board according to the embodiment may increase the separation distance between the plurality of via portions, and thus, it is easy to implement a fine pattern of the circuit pattern, thereby increasing the circuit density.

In addition, in the embodiment, the design freedom of the printed circuit board as a whole can be improved according to the design change of the via part, and thus fine pattern implementation and board reliability can be secured.

In addition, in the embodiment, the centers of the via portions directly connected to each other in the vertical direction may be arranged to be aligned on the same vertical line, or alternatively, may be arranged in a zigzag manner to be shifted from each other. Here, the aligned or zigzag-arranged portions may be non-apartments of respective vias, and may alternatively be pads of each via, and otherwise include both non-apartments and pads of each via. Accordingly, the shape or position of the via part can be freely changed according to the design of the circuit pattern required in the printed circuit board including the via part, and thus the degree of design freedom can be improved.

4 to 10 are views showing the manufacturing method of the printed circuit board according to the first embodiment shown in FIG. 2 in order of process.

First, referring to FIG. 4A , the first insulating layer 111 serving as the basis of the printed circuit board is prepared.

The first insulating layer 111 may be a prepreg. The first insulating layer 111 may be a thermosetting resin. The prepreg (PPG) has good flowability and adhesion in a semi-cured state, and is used as an intermediate substrate for a fiber-reinforced composite material used as an adhesive layer and an insulating material layer. . A molded article is formed by laminating these prepregs and curing the resin by heating/pressing. That is, the prepreg refers to a material that is impregnated with resin (BT/Epoxy, FR4, FR5, etc.) into glass fiber and cured to B-stage.

In addition, the first insulating layer 111 may be a thermosetting or thermoplastic polymer substrate, a ceramic substrate, an organic-inorganic composite material substrate, or a glass fiber-impregnated substrate, and if it contains a polymer resin, it may contain an epoxy-based insulating resin. Alternatively, the polyimide-based resin may be included.

That is, the first insulating layer 111 is a plate on which an electric circuit capable of changing wiring is formed, and includes all printed circuit boards and insulating substrates made of an insulating material capable of forming a conductor pattern on the surface of the insulating substrate. can do.

Meanwhile, as shown in (b) of FIG. 4 , a metal layer 101 may be stacked on the surface of the first insulating layer 111 . The metal layer 101 may be formed by electroless plating a metal including copper on the surface of the first insulating layer 111 . Also, unlike the formation of the metal layer 101 by electroless plating on the first insulating layer 111 , copper clad laminate (CCL) may be used.

When the metal layer 101 is formed by electroless plating, roughness is provided to the upper surface of the first insulating layer 111 so that plating can be performed smoothly.

Hereinafter, a method of manufacturing the printed circuit board 100 according to the embodiment with the first insulating layer 111 on which the metal layer 101 is not formed will be described.

Next, referring to FIG. 5 , at least one first via hole VH1 may be formed in the first insulating layer 111 . The first via hole VH1 may be formed to pass through the upper and lower surfaces of the first insulating layer 111 .

The first via hole VH1 may be formed by any one of mechanical, laser, and chemical processing methods. When the first via hole VH1 is formed by machining, methods such as milling, drilling, and routing may be used, and when formed by laser processing, UV or CO _{A two-} laser method may be used, and in the case of being formed by chemical processing, the first insulating layer 111 may be opened using chemicals including aminosilane, ketones, and the like.

On the other hand, the processing by the laser is a cutting method in which a part of the material is melted and evaporated by concentrating optical energy on the surface to take a desired shape, and complex formation by a computer program can be easily processed, and in other methods, cutting Even difficult composite materials can be machined.

In addition, the processing by the laser can have a cutting diameter of at least 0.005mm, and has a wide advantage in a range of possible thicknesses.

As the laser processing drill, it is preferable to use a YAG (Yttrium Aluminum Garnet) laser, a CO ₂ laser, or an ultraviolet (UV) laser. The YAG laser is a laser that can process both the copper foil layer and the insulating layer, and the CO ₂ laser is a laser that can process only the insulating layer.

Next, referring to FIG. 6 , the first via hole VH1 formed in the first insulating layer 111 is filled with a metal material to form the first via part 120 . In this case, the first via part 120 is disposed on the first via part 121 passing through the first insulating layer 111 , and on the upper and lower surfaces of the first insulating layer 111 , respectively. It includes first pads 122 and 123 connected to the first via part 121 .

The first via part 121 may be formed by filling the first via hole VH1 penetrating the first insulating layer 111 with a conductive material.

The metal material forming the first via part 121 may be any one material selected from copper (Cu), silver (Ag), tin (Sn), gold (Au), nickel (Ni), and palladium (Pd). The conductive material may be filled using any one or a combination of electroless plating, electrolytic plating, screen printing, sputtering, evaporation, inkjetting and dispensing. can

In addition, the first via part 120 may include first pads 122 and 123 disposed on the upper and lower surfaces of the first insulating layer 111 . Preferably, the first-first pad 122 connected to the upper surface of the first via part 121 may be disposed on the upper surface of the first insulating layer 111 . The first-first pad 122 may be one of a plurality of circuit patterns disposed on the upper surface of the first insulating layer 111 .

Also, a 1-2 th pad 123 connected to a lower surface of the first via part 121 may be disposed on a lower surface of the first insulating layer 111 . The 1-2 first pad 123 may be one of a plurality of circuit patterns disposed on the lower surface of the first insulating layer 111 .

The width of the upper surface and the lower surface of the first via part 121 may be different from each other. Preferably, a top surface of the first via part 121 may have a first width W1 . In addition, a lower surface of the first via part 121 may have a second width W2 smaller than the first width W1 . That is, the first via part 121 may have a cylindrical shape in which the width gradually decreases from the upper surface to the lower surface. Accordingly, the first width W1 and the second width W2 may mean a diameter of an upper surface and a diameter of a lower surface of the first via part 121 , respectively.

The first-first pad 122 may be a capture pad of the first via part 120 . The width of the upper surface and the lower surface of the first-first pad 122 may be the same. Preferably, the first-first pad 122 may have a first width W1 corresponding to a top surface of the first via part 121 .

The first-second pad 123 may be a land pad of the first via part 120 . The width of the upper surface and the lower surface of the first-second pad 123 may be the same. Preferably, the 1-2 first pad 123 may have a first width W1 corresponding to the top surface of the first via part 121 .

That is, the first-first pad 122 and the first-second pad 123 may have a first width W1 corresponding to the top surface of the first via part 121 .

As described above, in the embodiment, the width of the first-first pad 122 is the same as the width of the upper surface of the first via part 121 . Accordingly, in the embodiment, the separation distance W3 between the plurality of first via portions 120 disposed in the first insulating layer 111 may be increased compared to the comparative example illustrated in FIG. 1 . That is, in the embodiment, the separation distance between the top surfaces of the plurality of first via parts and the separation distance between the plurality of first-first pads may be the same. Accordingly, in the embodiment, the separation distance between the plurality of first via portions may be increased, thereby improving other circuit density and design freedom.

Next, as shown in FIG. 7 , a second insulating layer 112 is disposed on the upper surface of the first insulating layer 111 , and a third insulating layer 113 is disposed below the lower surface of the first insulating layer 111 . ) is placed. In this case, the second insulating layer 112 and the third insulating layer 113 may include a photocurable resin or a photosensitive resin. To this end, the second insulating layer 112 and the third insulating layer 113 may include an epoxy resin, a photoinitiator, a silicon-based filler, a curing agent, and the like. For example, the second insulating layer 112 and the third insulating layer 113 may be formed by laminating a photocurable resin film or applying a photocurable resin paste or liquid. At this time, in one example, the photocurable resin material is photocurable polyhydroxystyrene (PHS), photocurable polybenzoxazole (PBO), photocurable polyimide (PI), photocurable benzocyclobutene (BCB), photocurable It may include any one or more selected from chemical conversion polysiloxane, photocurable epoxy, and novolac resin.

In addition, a second via hole VH2 penetrating through the upper and lower surfaces of the second insulating layer 112 may be formed in the second insulating layer 112 . In this case, the second via hole VH2 may be formed to expose the first-first pad 122 constituting the first via part 120 .

In addition, a third via hole VH3 penetrating through the upper and lower surfaces of the third insulating layer 113 may be formed in the third insulating layer 113 . In this case, the third via hole VH3 may be formed while exposing the 1-2 first pad 123 constituting the first via part 120 .

In this case, the second insulating layer 112 and the third insulating layer 113 are formed of a photocurable resin, and accordingly, the second via hole VH2 and the third via hole VH3 are formed by exposure and development processes, etc. As it is formed through the , its depth can be easily adjusted, and accordingly, the widths of the 1-1 pad 122 and the 1-2 pad 123, which have previously served as a stopper therefor, can be freely formed.

Next, as shown in FIG. 8 , a second via part 130 is formed in the second via hole VH2 formed in the second insulating layer 112 , and a third via part 130 formed in the third insulating layer 113 is formed. A third via portion 140 is formed in the via hole VH3 .

In this case, the second via part 130 includes a second via part 131 that passes through the second insulating layer 112 , and a second via part that is disposed on the upper surface of the second insulating layer 112 and is disposed on the second via. A second pad 132 connected to the upper surface of the part 131 may be included. In this case, the lower surface of the second via part 131 may be disposed in direct contact with the upper surface of the first-first pad 122 of the first via part 120 . The upper and lower surfaces of the second via part 131 may have different widths. Preferably, an upper surface of the second via part 131 may have a first width W1 , and a lower surface of the second via part 131 may have a second width W2 smaller than the first width W1 . ) can have The second pad 132 disposed on the upper surface of the second via part 131 may have a first width W1 corresponding to the upper surface of the second via part 131 . A lower surface of the second pad 132 may directly contact an upper surface of the second via part 131 . Specifically, the lower surface of the second pad 132 may contact only the upper surface of the second via part 131 while not in contact with the upper surface of the second insulating layer 112 .

In addition, the third via part 140 includes a third via part 141 that passes through the third insulating layer 113 , and a third via part 141 that is disposed on a lower surface of the third insulating layer 113 . A third pad 142 connected to the lower surface of the part 141 may be included.

In this case, the upper surface of the third via part 141 may be disposed in direct contact with the lower surface of the first second pad 123 of the first via part 120 .

The upper and lower surfaces of the third via part 141 may have different widths. Preferably, an upper surface of the third via part 141 may have a second width W2 , and a lower surface of the third via part 141 may have a first width W1 greater than the second width W2 . ) can have

The third pad 142 disposed on the lower surface of the third via part 141 may have a first width W1 corresponding to the lower surface of the third via part 141 . An upper surface of the third pad 142 may directly contact a lower surface of the third via part 141 . Specifically, the upper surface of the third pad 142 may contact only the lower surface of the third via part 141 while not in contact with the lower surface of the third insulating layer 113 .

Next, as shown in FIG. 9 , a fourth insulating layer 114 is disposed on the upper surface of the second insulating layer 112 , and a fifth insulating layer 115 is disposed below the lower surface of the third insulating layer 113 . ) is placed. In this case, the fourth insulating layer 114 and the fifth insulating layer 115 may include a photocurable resin or a photosensitive resin. To this end, the fourth insulating layer 114 and the fifth insulating layer 115 may include an epoxy resin, a photoinitiator, a silicon-based filler, a curing agent, and the like. For example, the fourth insulating layer 114 and the fifth insulating layer 115 may be formed by laminating a photocurable resin film or applying a photocurable resin paste or liquid. At this time, in one example, the photocurable resin material is photocurable polyhydroxystyrene (PHS), photocurable polybenzoxazole (PBO), photocurable polyimide (PI), photocurable benzocyclobutene (BCB), photocurable It may include any one or more selected from chemical conversion polysiloxane, photocurable epoxy, and novolac resin.

In addition, a fourth via hole VH4 penetrating the upper and lower surfaces of the fourth insulating layer 114 may be formed in the fourth insulating layer 114 . In this case, the fourth via hole VH4 may be formed to expose the second pad 132 constituting the second via part 130 .

In addition, a fifth via hole VH5 penetrating through the upper and lower surfaces of the fifth insulating layer 115 may be formed in the fifth insulating layer 115 . In this case, the fifth via hole VH5 may be formed to expose the third pad 142 constituting the third via part 140 .

In this case, the fourth insulating layer 114 and the fifth insulating layer 115 are formed of a photocurable resin, and accordingly, the fourth via hole VH4 and the fifth via hole VH5 are formed through an exposure and development process, etc. As it is formed through the , its depth can be easily adjusted, and accordingly, the widths of the second pad 132 and the third pad 142 that have previously served as a stopper can be freely formed.

Next, as shown in FIG. 10 , a fourth via 150 is formed in the fourth via hole VH4 formed in the fourth insulating layer 114 , and a fifth via 150 is formed in the fifth insulating layer 115 . A fifth via part 160 is formed in the via hole VH5 .

The fourth via part 150 includes a fourth via part 151 that passes through the fourth insulating layer 114 , and a fourth via part 151 that is disposed on the upper surface of the fourth insulating layer 114 . A fourth pad 152 connected to the upper surface of the 151 may be included.

In this case, the lower surface of the fourth via part 151 may be disposed in direct contact with the upper surface of the second pad 132 of the second via part 130 .

The upper and lower surfaces of the fourth via part 151 may have different widths. Preferably, an upper surface of the fourth via part 151 may have a first width W1 , and a lower surface of the fourth via part 151 may have a second width W2 smaller than the first width W1 . ) can have

The fourth pad 152 disposed on the upper surface of the fourth via part 151 may have a first width W1 corresponding to the upper surface of the fourth via part 151 . A lower surface of the fourth pad 152 may directly contact an upper surface of the fourth via part 151 . Specifically, the lower surface of the fourth pad 152 may contact only the upper surface of the fourth via part 151 while not in contact with the upper surface of the fourth insulating layer 114 .

In addition, similarly to the second via part 130 , a fourth via hole constituting the fourth via part 151 is irrespective of the width of the second pad 132 of the second via part 130 . VH4) may be stably formed, and accordingly, the width of the second pad 132 may be the same as that of the upper surface of the second via part 131 .

Meanwhile, a fifth via portion 160 is disposed in the fifth insulating layer 115 . The fifth via part 160 includes a fifth via part 161 that passes through the fifth insulating layer 115 , and a fifth via part 161 that is disposed on a lower surface of the fifth insulating layer 115 . A fifth pad 162 connected to the lower surface of the 161 may be included.

In this case, the upper surface of the fifth via part 161 may be disposed in direct contact with the lower surface of the third pad 142 of the third via part 140 .

The upper and lower surfaces of the fifth via part 161 may have different widths. Preferably, an upper surface of the fifth via part 161 may have a second width W2 , and a lower surface of the fifth via part 161 may have a first width W1 greater than the second width W2 . ) can have

The fifth pad 162 disposed on the lower surface of the fifth via part 161 may have a first width W1 corresponding to the lower surface of the fifth via part 161 . An upper surface of the fifth pad 162 may directly contact a lower surface of the fifth via part 161 . Specifically, the upper surface of the fifth pad 162 may contact only the lower surface of the fifth via part 161 while not in contact with the lower surface of the fifth insulating layer 115 .

Also, like the second via part 130 or the fourth via part 150 , the fifth via part 161 is irrespective of the width of the third pad 142 of the third via part 140 . It is possible to stably form the fifth via hole VH5 constituting the . Accordingly, the width of the third pad 142 may be the same as that of the lower surface of the third via part 141 .

According to an embodiment, in a printed circuit board having a multilayer structure, each via portion interconnected includes a via part penetrating an insulating layer and a pad disposed on one surface of the via part. In this case, in the printed circuit board according to the embodiment, the width of the pad is not greater than the width of the one surface of the via part. In other words, the width of each via part included in the printed circuit board may be equal to or smaller than the width of one surface of the via part.

According to this, the printed circuit board according to the embodiment may increase the separation distance between the plurality of via portions, and thus, it is easy to implement a fine pattern of the circuit pattern, thereby increasing the circuit density.

In addition, in the embodiment, the design freedom of the printed circuit board as a whole can be improved according to the design change of the via part, and thus fine pattern implementation and board reliability can be secured.

In addition, in the embodiment, the centers of the via portions directly connected to each other in the vertical direction may be arranged to be aligned on the same vertical line, or alternatively, may be arranged in a zigzag manner to be shifted from each other. Here, the aligned or zigzag-arranged portions may be non-apartments of respective vias, and may alternatively be pads of each via, and otherwise include both non-apartments and pads of each via. Accordingly, the shape or position of the via part can be freely changed according to the design of the circuit pattern required in the printed circuit board including the via part, and thus the degree of design freedom can be improved.

Hereinafter, various modified embodiments will be described with reference to the structure of the printed circuit board according to the first embodiment described with reference to FIG. 2 .

In the following description of the printed circuit board, the same reference numerals will be given to parts substantially identical to those of the previous embodiment.

11 is a view showing a printed circuit board according to a second embodiment.

Referring to FIG. 11 , the printed circuit board 100A includes an insulating layer 110 , via portions 120a , 130 , 140 , 150 , 160 , and a circuit pattern 135 .

The insulating layer 110 includes a first insulating layer 111 , a second insulating layer 112 , a third insulating layer 113 , a fourth insulating layer 114 , and a fifth insulating layer 115 .

The via parts 120a, 130, 140, 150, and 160 include a first via part 120a disposed in the first insulating layer 111, a second via part 130 disposed in the second insulating layer 112, The third via 140 disposed in the third insulating layer 113 , the fourth via 150 disposed in the fourth insulating layer 114 , and the fifth via disposed in the fifth insulating layer 115 . (160).

Here, in the printed circuit board 100A of the second embodiment, except for the first via part 120a, other configurations are the same as those of the printed circuit board 100 according to the first embodiment in FIG. 2, and accordingly, in the following Only the first via part 120a will be described.

The first via part 120a includes the first via part 121 disposed in the first insulating layer 111 and the first pads 122 and 123a disposed on the upper and lower surfaces of the first insulating layer 111 . include

The first pads 122 and 123a are disposed on the upper surface of the first insulating layer 111 and include a first-first pad 122 in contact with the upper surface of the first via part 121 . The width of the first-first pad 122 may be the same as the width of the top surface of the first via part 121 .

In addition, the first pads 122 and 123a include first-second pads 123a disposed on the lower surface of the first insulating layer 111 and contacting the lower surface of the first via part 121 . The width of the first-second pad 123a may be the same as the width of the lower surface of the first via part 121 .

That is, the width of the first-second pad 123 in FIG. 2 was the same as the width of the upper surface of the first via part 121 and the width of the first-first pad 122 .

Alternatively, the width of the 1-2 th pad 123 according to the second embodiment in FIG. 11 is the width of the lower surface of the first via part 121 and the third of the third via part 140 . The width W2 of the top surface of the via part 141 may be the same. That is, as the third via hole VH3 is formed through the exposure and development process, the width of the first-2 pads 123a, which served as a stopper for forming the third via hole VH3 in the comparative example, can be freely adjusted. It may have the same width as the lower surface of the first via part 121 .

12 is a view showing a printed circuit board according to a third embodiment.

Referring to FIG. 12 , the printed circuit board 100B includes an insulating layer 110 , via portions 120b , 130b , 140b , 150 , 160 , and a circuit pattern 135 .

The insulating layer 110 includes a first insulating layer 111 , a second insulating layer 112 , a third insulating layer 113 , a fourth insulating layer 114 , and a fifth insulating layer 115 .

The via parts 120b, 130b, 140b, 150, and 160 include a first via part 120b disposed in the first insulating layer 111 , a second via part 130b disposed in the second insulating layer 112 , The third via 140b disposed in the third insulating layer 113 , the fourth via 150 disposed in the fourth insulating layer 114 , and the fifth via disposed in the fifth insulating layer 115 . (160).

Here, in the printed circuit board 100B of the second embodiment, the configuration other than the first via part 120b, the second via part 130b and the third via part 140b is the first embodiment shown in FIG. 2 . It is the same as that of the printed circuit board 100 according to , and accordingly, only the first via part 120b, the second via part 130b, and the third via part 140b will be described below.

The first via part 120b includes the first via part 121 disposed in the first insulating layer 111 and first pads 122b and 123b disposed on the upper and lower surfaces of the first insulating layer 111 . include

The first pads 122b and 123b include a first-first pad 122b disposed on the upper surface of the first insulating layer 111 and contacting the upper surface of the first via part 121 . A width of the first-first pad 122b may be smaller than a width of a top surface of the first via part 121 .

Preferably, the width of the first-first pad 122b may be the same as the width of the lower surface of the second via part 131 of the second via part 130b. In other words, the width of the first-first pad 122b may have the same second width W2 as the width of the lower surface of the first via part 121 and the width of the first-second pad 123b. .

Accordingly, the upper surface of the first via part 121 in the first or second embodiment only contacts the lower surface of the 1-1 pad 122 , but the first via part 121 in the third embodiment ) may include a first area in contact with a lower surface of the second insulating layer 112 and a second area in contact with the first-first pad 122b.

In addition, the first pads 122b and 123b include first-second pads 123b disposed on the lower surface of the first insulating layer 111 and contacting the lower surface of the first via part 121 . The width of the first-second pad 123b may be the same as the width of the lower surface of the first via part 121 .

In addition, the second via part 130b may include a second via part 131 and a second pad 132b disposed on an upper surface of the second via part 131 . In this case, the second pad 132b is not the same width as the top surface of the second via part 131 , but is not the same width as the lower surface of the fourth via part 151 of the fourth via part 150 or the second via part ( 131) may have the same width as the lower surface.

Also, the third via part 140b may include a third via part 141 and a third pad 142b disposed under a lower surface of the third via part 141 . In this case, the third pad 142b is not the same width as the lower surface of the third via part 141 but the upper surface of the fifth via part 161 of the fifth via part 160 or the third via part ( 141) may have the same width as the upper surface.

As described above, in the third embodiment, the widths of the first pads 122b and 123b, the second pad 132b and the third pad 142b are adjusted to the second width W2 instead of the first width W1. can

13 is a view showing a printed circuit board according to a fourth embodiment.

Referring to FIG. 13 , the printed circuit board 100C includes an insulating layer 110 , via portions 120c , 130c , 140c , 150c , 160c , and a circuit pattern 135 .

The insulating layer 110 includes a first insulating layer 111 , a second insulating layer 112 , a third insulating layer 113 , a fourth insulating layer 114 , and a fifth insulating layer 115 .

The via parts 120c, 130c, 140c, 150c, and 160c include a first via part 120c disposed in the first insulating layer 111 , a second via part 130c disposed in the second insulating layer 112 , The third via part 140c disposed in the third insulating layer 113 , the fourth via part 150c disposed in the fourth insulating layer 114 , and the fifth via part disposed in the fifth insulating layer 115 . (160c).

Here, in the printed circuit board 100C of the fourth embodiment, other configurations except for the via portions 120c, 130c, 140c, 150c, and 160c are the same as the printed circuit board 100 according to the first embodiment in FIG. 2 . Accordingly, hereinafter, only the via portions 120c, 130c, 140c, 150c, and 160c will be described.

The first via part 120c includes the first via part 121 disposed in the first insulating layer 111 and the first pads 122c and 123c disposed on the upper and lower surfaces of the first insulating layer 111 . include

The first pads 122c and 123c are disposed on the upper surface of the first insulating layer 111 and include a first-first pad 122c in contact with the upper surface of the first via part 121 . A width of the first-first pad 122c may be smaller than a width of a top surface of the first via part 121 .

Preferably, the width of the first-first pad 122c may be smaller than the width of the lower surface of the second via part 131c of the second via part 130c. That is, the width of the first-first pad 122c may have a fourth width W4 smaller than the first width W1 and the second width W2 .

Accordingly, the upper surface of the first via part 121 in the first or second embodiment only contacts the lower surface of the 1-1 pad 122 , but the first via part 121 in the fourth embodiment ) has a first region in contact with a lower surface of the second insulating layer 112 , a second region in contact with a lower surface of the 1-1 pad 122c and a lower surface of the second via part 131c . It may include a third region.

In addition, the first pads 122c and 123c include first-second pads 123c disposed on the lower surface of the first insulating layer 111 and contacting the lower surface of the first via part 121 . A width of the first-second pad 123c may be smaller than a width q of a lower surface of the first via part 121 . That is, the first-second pad 123c may have a fourth width W4 .

In addition, the second via part 130c may include a second via part 131c and a second pad 132c disposed on an upper surface of the second via part 131c. In this case, the second pad 132c may have a fourth width W4 smaller than the upper and lower surfaces of the second via part 131c and the lower surface of the fourth via part 151c. Accordingly, an upper surface of the second via part 131c has a first region in contact with a lower surface of the fourth insulating layer 114 , a second region in contact with a lower surface of the second pad 132c and a fourth via and a third region in contact with the lower surface of the part 151c.

Also, the third via part 140c may include a third via part 141c and a third pad 142c disposed under a lower surface of the third via part 141c. In this case, the third pad 142c may have a fourth width W4 smaller than the same width as the lower and upper surfaces of the third via part 141c. Accordingly, a lower surface of the third via part 141c has a first region in contact with the fifth insulating layer 115 , a second region in contact with the third pad 142c and a lower surface of the third via part 141c in contact with the fifth via part 161c . It may include a third region.

Also, the fourth via part 150c may include a fourth via part 151c and a second pad 152 disposed on an upper surface of the fourth via part 151c.

The fifth via part 150c may include a fifth via part 161c and a fifth pad 162 disposed under a lower surface of the fifth via part 161c.

As described above, in the fourth embodiment, the widths of the first pads 122c and 123c, the second pad 132c, and the third pad 142c are smaller than the first width W1 and the second width W2. The fourth width W4 may be adjusted to be small, and accordingly, it may have a structure surrounded by the via part disposed above or below the fourth width W4.

14 is a view showing a printed circuit board according to a fifth embodiment.

Referring to FIG. 14 , the printed circuit board 100D includes an insulating layer 110 , via portions 120c , 130c , 140c , 150d and 160d , and a circuit pattern 135 .

The insulating layer 110 includes a first insulating layer 111 , a second insulating layer 112 , a third insulating layer 113 , a fourth insulating layer 114 , and a fifth insulating layer 115 .

The via parts 120c, 130c, 140c, 150d, and 160d include a first via part 120c disposed in the first insulating layer 111 , a second via part 130c disposed in the second insulating layer 112 , The third via part 140c disposed in the third insulating layer 113 , the fourth via part 150d disposed in the fourth insulating layer 114 , and the fifth via part disposed in the fifth insulating layer 115 . (160d).

Here, in the printed circuit board 100D of the fifth embodiment, other configurations except for the via portions 120c, 130c, 140c, 150c, and 160c are the same as the printed circuit board 100 according to the fourth embodiment in FIG. 13 . Accordingly, only the fourth and fifth via portions 150d and 160d will be described below.

The fourth via part 150d may include a fourth via part 151c and a fourth pad 152d disposed on an upper surface of the fourth via part 151c.

The fifth via part 150d may include a fifth via part 161c and a fifth pad 162d disposed under a lower surface of the fifth via part 161c.

In this case, the fourth pad 152 and the fifth pad 162 in the fourth embodiment have a first width W1. Alternatively, the fourth pad 152d and the fifth pad 162d in the fifth embodiment may have a fourth width W4 smaller than the first width W1 and the second width W2.

15 is a view showing a printed circuit board according to a sixth embodiment.

Referring to FIG. 15 , the printed circuit board 100E includes an insulating layer 110 , via portions 120e , 130e , 140e , 150c , 160c , and a circuit pattern 135 .

The insulating layer 110 includes a first insulating layer 111 , a second insulating layer 112 , a third insulating layer 113 , a fourth insulating layer 114 , and a fifth insulating layer 115 .

The via parts 120e, 130e, 140e, 150 and 160c include a first via part 120e disposed in the first insulating layer 111 , a second via part 130e disposed in the second insulating layer 112 , The third via 140e disposed in the third insulating layer 113 , the fourth via 150c disposed in the fourth insulating layer 114 , and the fifth via disposed in the fifth insulating layer 115 . (160c).

Here, in the printed circuit board 100E of the sixth embodiment, other configurations except for the via portions 120e, 130e, and 140e are the same as the printed circuit board 100 according to the fourth embodiment in FIG. 13, and accordingly Hereinafter, only the via portions 120e, 130e, and 140e will be described.

The first via part 120e includes the first via part 121 disposed in the first insulating layer 111 and first pads 122e and 123e disposed on the upper and lower surfaces of the first insulating layer 111 . include

In this case, the centers of the first via part and the first pads in the previous embodiment are aligned on the same vertical line.

Alternatively, the virtual vertical line passing through the center of the first via part 121 may be parallel to the virtual vertical line passing through the center of the first pads 122e and 123e. For example, a virtual vertical line passing through the center of the first via part 121 may be horizontally spaced apart from a virtual vertical line passing through the center of the first pads 122e and 123e in a horizontal direction. For example, a virtual vertical line passing through the center of the first via part 121 and a virtual vertical line passing through the center of the first pads 122e and 123e may be displaced from each other.

Also, the second via part 130e may include a second via part 131c and a second pad 132e disposed on the upper surface of the second via part 131c. In this case, the center of the second pad 132e and the second via pod 131c may be displaced from each other similarly to the first via part 120e.

Also, the third via portion 140e may include a third via part 141c and a third pad 142e disposed under a lower surface of the third via part 141c. In this case, the center of the third pad 142e and the third via part 141c may be shifted from each other like the first via part 120e and the second via part 130e.

In this case, the centers of the respective via parts 121 , 131c , and 141c in the first to third via parts 120e , 130e , and 140e may be aligned on one and the same vertical line. Also, in the first to third via portions 120e, 130e, and 140e, the centers of the respective pads 122e, 123e, 132e, and 142e may be aligned on one and the same vertical line. However, the center of each of the via parts 121 , 131c and 141c and the center of each of the pads 122e , 123e , 132e and 142e may be displaced from each other.

Meanwhile, the lower surface of the second via part 131c overlaps the upper surface of the first-first pad 122e by at least 20% in the vertical direction. At this time, when the overlap area between the lower surface of the second via part 131c and the upper surface of the 1-1 pad 122e is less than 20%, the reliability of the connection between the first via part and the second via part may be lowered. can

16 is a view showing a printed circuit board according to a seventh embodiment.

Referring to FIG. 16 , the printed circuit board 100F includes an insulating layer 110 , via portions 120f , 130f , 140f , 150f , and 160f , and a circuit pattern 135 .

As described above, the via parts 120f, 130f, 140f, 150f, and 160f each include a via part and a pad.

In this case, the via part and the pad constituting each via part may be aligned on the same vertical line having one center.

However, the centers of the adjacent vias may be displaced.

For example, the centers of the first via part 121 and the first pads 122 and 123 constituting the first via part 120f may be aligned on one and the same first vertical line CL1 .

Also, the centers of the second via part 131 and the second pad 132 constituting the second via part 130f may be aligned on one and the same second vertical line CL2 .

However, the first vertical line CL1 and the second vertical line CL2 may be spaced apart from each other by a predetermined interval in the horizontal direction.

According to an embodiment, in a printed circuit board having a multilayer structure, each via portion interconnected includes a via part penetrating an insulating layer and a pad disposed on one surface of the via part. In this case, in the printed circuit board according to the embodiment, the width of the pad is not greater than the width of the one surface of the via part. In other words, the width of each via part included in the printed circuit board may be equal to or smaller than the width of one surface of the via part.

According to this, the printed circuit board according to the embodiment may increase the separation distance between the plurality of via portions, and thus, it is easy to implement a fine pattern of the circuit pattern, thereby increasing the circuit density.

In addition, in the embodiment, the design freedom of the printed circuit board as a whole can be improved according to the design change of the via part, and thus fine pattern implementation and board reliability can be secured.

In addition, in the embodiment, the centers of the via portions directly connected to each other in the vertical direction may be arranged to be aligned on the same vertical line, or alternatively, may be arranged in a zigzag manner to be shifted from each other. Here, the aligned or zigzag-arranged portions may be non-apartments of respective vias, and may alternatively be pads of each via, and otherwise include both non-apartments and pads of each via. Accordingly, the shape or position of the via part can be freely changed according to the design of the circuit pattern required in the printed circuit board including the via part, and thus the degree of design freedom can be improved.

Features, structures, effects, etc. described in the above embodiments are included in at least one embodiment, and are not necessarily limited to only one embodiment. Furthermore, features, structures, effects, etc. illustrated in each embodiment can be combined or modified for other embodiments by those of ordinary skill in the art to which the embodiments belong. Accordingly, the contents related to such combinations and modifications should be interpreted as being included in the scope of the embodiments.

In the above, the embodiment has been mainly described, but this is only an example and not limiting the embodiment, and those of ordinary skill in the art to which the embodiment belongs may have several examples not illustrated above in the range that does not deviate from the essential characteristics of the embodiment. It can be seen that variations and applications of branches are possible. For example, each component specifically shown in the embodiment can be implemented by modification. And differences related to such modifications and applications should be construed as being included in the scope of the embodiments set forth in the appended claims.

Claims (18)

a first insulating layer;
a second insulating layer disposed over the first insulating layer;
a first via portion disposed in the first insulating layer; and
a second via portion disposed in the second insulating layer;
The first via part,
a first via part passing through the first insulating layer;
a 1-1 pad disposed on the upper surface of the first insulating layer and connected to the upper surface of the first via part;
and first and second pads disposed on a lower surface of the first insulating layer and connected to a lower surface of the first via part;
The second via part,
a second via part passing through the second insulating layer and having a lower surface connected to the upper surface of the 1-1 pad;
a second pad disposed on the upper surface of the second insulating layer and connected to the upper surface of the second via part;
The 1-1 pad,
less than or equal to the width of the upper surface of the first via part;
The second pad,
less than or equal to the width of the upper surface of the second via part
printed circuit board. According to claim 1,
each of the first via part and the second via part,
an upper surface having a first width;
including a lower surface having a second width smaller than the first width
printed circuit board. 3. The method of claim 2,
Each of the 1-1 pad and the second pad,
having a third width smaller than the first width or the second width
printed circuit board. 4. The method of claim 3,
A top surface of the first via part is
a first region in contact with a lower surface of the second insulating layer;
and a second region in contact with a lower surface of the second pad.
printed circuit board. 5. The method of claim 4,
A top surface of the first via part is
and a third region in contact with an upper surface of the second via part.
printed circuit board. 4. The method of claim 3,
a third insulating layer disposed under the first insulating layer; and
a third via portion disposed in the third insulating layer;
The third via part,
a third pad disposed on a lower surface of the third insulating layer;
a third via part disposed in the third insulating layer, a lower surface connected to the upper surface of the third pad, and a third via part having an upper surface connected to the first-second pad
printed circuit board. 7. The method of claim 6,
The 1-2 pad,
the second width or a third width smaller than the second width;
printed circuit board. 8. The method of claim 7,
A lower surface of the first via part,
a first region in contact with an upper surface of the third insulating layer;
a second region in contact with the upper surface of the third pad;
and a third region in contact with an upper surface of the third via part.
printed circuit board. 7. The method of claim 6,
The second insulating layer and the third insulating layer include a photo-curable resin (PID: Photoimageable dielectics)
printed circuit board. 10. The method of claim 9,
The first insulating layer includes a thermosetting resin
printed circuit board. 7. The method of claim 6,
Each center of the 1-1 pad, the 1-2 pad, the first via part, the second via part, the second pad, the third via part, and the third pad has one and the same vertical line. sorted on
printed circuit board. preparing a first insulating layer;
forming a first via hole in the first insulating layer;
forming a first via portion filling the first via hole in the first insulating layer;
forming a second insulating layer on an upper surface of the first insulating layer and forming a third insulating layer below the lower surface of the first insulating layer;
forming a second via hole in the second insulating layer and forming a third via hole in the third insulating layer;
forming a second via part filling the second via hole in the second insulating layer and forming a third via part filling the third via hole in the third insulating layer;
The first via part,
a first via part passing through the first insulating layer;
a 1-1 pad disposed on the upper surface of the first insulating layer and connected to the upper surface of the first via part;
and first and second pads disposed on a lower surface of the first insulating layer and connected to a lower surface of the first via part;
The second via part,
a second via part passing through the second insulating layer and having a lower surface connected to the upper surface of the 1-1 pad;
a second pad disposed on the upper surface of the second insulating layer and connected to the upper surface of the second via part;
The third via part,
a third pad disposed on a lower surface of the third insulating layer;
a third via part disposed in the third insulating layer, a lower surface connected to an upper surface of the third pad, and a third via part having an upper surface connected to the first-2 pads;
The 1-1 pad,
less than or equal to the width of the upper surface of the first via part;
The second pad,
less than or equal to the width of the upper surface of the second via part;
The third pad,
It is smaller than or equal to the width of the lower surface of the third via part.
A method for manufacturing a printed circuit board. 13. The method of claim 12,
each of the first via part and the second via part,
an upper surface having a first width;
Including a lower surface having a second width smaller than the first width,
The third via part is
an upper surface having the second width;
including a lower surface having the first width
A method for manufacturing a printed circuit board. 14. The method of claim 13,
Each of the 1-1 pad and the second pad,
having a third width smaller than the first width or the second width;
The 1-2 pad,
the second width or a third width smaller than the second width;
A method for manufacturing a printed circuit board. 15. The method of claim 14,
A top surface of the first via part is
a first region in contact with a lower surface of the second insulating layer;
a second region in contact with a lower surface of the second pad;
and a third region in contact with an upper surface of the second via part.
A method for manufacturing a printed circuit board. 15. The method of claim 14,
A lower surface of the first via part,
a first region in contact with an upper surface of the third insulating layer;
a second region in contact with the upper surface of the third pad;
and a third region in contact with an upper surface of the third via part.
A method for manufacturing a printed circuit board. 17. The method of claim 16,
The second insulating layer and the third insulating layer include a photo-curable resin (PID: Photoimageable dielectics),
The first insulating layer includes a thermosetting resin
A method for manufacturing a printed circuit board. 13. The method of claim 12,
Each center of the 1-1 pad, the 1-2 pad, the first via part, the second via part, the second pad, the third via part, and the third pad has one and the same vertical line. sorted on
A method for manufacturing a printed circuit board.

Images